1. Field of the Invention
This invention relates to novel bromosalicylanilide derivatives which are useful as biocidal agents and particularly useful as fungicides and bactericides.
2. Description of the Prior Art
It is known in the prior art that certain brominesubstituted salicylanilide compounds are useful in the biocidal area. For example, di- and tri-bromosalicylanilides are described in U.S. Pat. No. 2,906,711 as being useful as germicides. Further, U.S. Pat. No. 3,041,236 discloses that dibromo salicylanilides containing a trifluoromethyl group are bactericides. Also, British Pat. No. 840,366 discloses 3,4',5-tribromosalicylanilide as useful in germicidal preparations. In general, these halogenated salicylanilides are prepared by halogenation of the corresponding salicylanilide compounds as disclosed in these references. However, as indicated in these patents the halogenation process of the prior art generally result in the preparation of only mixtures of products which comprise isomeric halogenated products having varying degrees of halogenation. This is illustrated for example by U.S. Pat. No. 2,967,885 which describes a method for bromination of salicylanilide where it is specifically indicated that by suitable control of the reaction, a major portion of the product is 3,4',5-tribromosalicylanilide but that other products, including 3,5- and 4',5-dibromosalicylanilides and 2',3,4',5-tetrabromosalicylanilide are also produced in the process. Hence only mixtures are obtained. Therefore, while the prior art has recognized that dibromosalicylanilides do exhibit biocidal properties the art has not disclosed suitable procedures by which these compounds can be prepared in high purity. Further, the art has not disclosed processes for preparation of compounds of this type which contain sulfonic acid groups and therefore are watersoluble for wider use areas.